Hypegrowth - Hypegrowth is a personal Twitter assistant that allows to grow Twitter audience.
Janetter - Janetter is a Twitter client application. Faster, smarter, and more powerful.
Jooicer - Superpowers to boost your Twitter Growth
YoruFukurou - YoruFukurou (NightOwl) is a Twitter client for Mac OS X, designed for Twitter addicts.
Toolset.co - Twitter growth made easy, a bunch of tools to easily manage and grow your Twitter account.
Tweeticide - Tweeticide – Delete All Tweets is a commercial app that enables you to delete all of your tweets at once.